You can selectively autoscale only a single axis, e.g., the xaxis by
setting scaley to False. The autoscaling preserves any
axis direction reversal that has already been done.

If tight is False, the axis major locator will be used
to expand the view limits if rcParams['axes.autolimit_mode']
is 'round_numbers'. Note that any margins that are in effect
will be applied first, regardless of whether tight is
True or False. Specifying tight as True or False
saves the setting as a private attribute of the Axes; specifying
it as None (the default) applies the previously saved value.

The data limits are not updated automatically when artist data are
changed after the artist has been added to an Axes instance. In that
case, use matplotlib.axes.Axes.relim() prior to calling
autoscale_view.